. "compactness theorem" . . . . . . "countable compactness" . "compact" . . "Compactness of first-order logic" . . "Compactness theorem" . . "compactness" . "Compactness theorem" . . . . . . . . . "logical compactness" . . "incompactness" . "(countable) compactness property" . . "compactness argument" .